Manufacture of flexible bituminous roofing and waterproofing materials.



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CHARLES N. FORREST, OF RAHWAY, NEW JERSEY, ASSIGNOR OF ONE-FOURTH TO ROBERT L. FOWLER AND ONE-FOURTH TO MARIUS S. DARROW, BOTH OF PERTH AMBOY, NEW JERSEY, AND ONE-FOURTH T0 EDMUND B. ROSEVEAR, OF BOON- ron, NEW JERSEY.

MANUFACTURE OF FLEXIBLE BITUMINOUS ROOFING AND WATERPROOFING Patented Jan. '9, 1917.

MATERIALS.

1,211,831. Specification of Letters Patent.

No Drawing. Application filed February 26, 1916.

by saturating) with bituminous material a flexible absor ent sheet of felt, and my invention relates particularly to the formation and composition of the felt which is to be subsequently so treated with bituminous materials. To this end I provide a continuous sheet of the desired thickness, say from' about one-sixteenth of an inch to one-eighth of an "inch, and of a highly absorbent or bibulous nature, composed of fibrous materials of sufficient length to felt together, and possessing sufiicient tensile strength. Heretofore these felted sheets have been prepared mainly from cotton and wool rags after the same have been beaten into fibrous pulp in a beating engine, as common in the paper industry. To these materials there has ordinarily been added a small amount of jute or other ligneous fibers or wood pulp. Materials of the latter class have heretofore been required both for economical reasons and to harden and strengthen the felt. Such materials are however, objectionable in that they are not absorbent of bitumen, nor are they as durable as is vdesired. I have found that a similar sheet of absorbent material composed of cotton and wool fibers reinforced with leather fibers is a much better material for the purpose specified than one containing jute or, wood pulp.

The leather fibers may be prepared from any kind of leather scrap althou h a soft scrap such as skivings is preferab e. They may be shredded in any type of beatin engine that will disintegrate leather an rag stock.

In practising my invention I proceed with a batch of say 858 pounds, made of approximately 150 pounds stockings, 550 pounds colored rags #2, 38 pounds wool waste and 120 pounds skivings or other soft leather scrap, but may vary the proportions as necis essential.

Serial N 0. 80,589.

essary or as desired up to 50 per cent. leather scrap. These materials are placed in a beater without any preliminary treatment, and beaten for from three to four hours as may be necessary to bring them to a properly shredded condition, water also being used in the boaters in the usual manner. The stock is then run out of the beater and dried in sheets of any desired width and thickness within the limits mentioned. Said sheets consist of a sheet of felt strong because of the shredded leather fiber, and highly absorbent or bibulous because of the open character of the resultant felt. This A sized or calendered material, or a material the interstices of which have been filled with cementitious matter, would not answer my purpose. After the sheets are thus formed and dried, they are immersed in a bath of melted bitumen or equivalent material, and thoroughly saturated with such bitumen for use as roofing or any other purposes for which such a product is serviceable, the amount of saturant in the finished goods being usually in excess of 50 per cent. by Weight.

In order to be strong enough to be subjected to the operation of passing through a bath of melted bitumen, which may involve' a temperature of three or four hundred degrees F., the felt must have inherent tensile strength, for which purpose the leather fibers are superior to the pulp and cellulose fibers heretofore used.

I am .aware that in the manufacture of leather board leather fibers and cellulose have heretofore been combined, but the pulp has been so fine as to lack suflicient strength for treatment such as has been described; also such leather board is not absorbent, not being adapted to or intended for treatment such as I have described.

The leather component in the absorbent felt serves three useful purposes, it increases the strength ofthe material, it is more absorbent of bitumen than other materials which have previously been used in the endeavor to increase the strength of the felt, andit reduces the cost.

Having thus describedmy invention, I claim:

1. A material of the class described, composed of a highly absorbent flexible sheet comprising fibers of cotton or wool and leather felted together and saturated with a bituminous material. 2. A roofing or water-proofing material composed of a highly absorbent felt containing from ten to fifty per cent. of leather fibers and from ninety to fifty per cent. of mixed wool cotton fibers felted together, and saturated with bituminous water-proofing materials.

3. A material of the class described consisting of felted fibers of cotton and wool combined with from ten to fifty per cent. of leather fibers in the form of an absorbent flexible sheet and saturated with bitumen to render it water-proof.

7 4. The process of manufacturing flexible roofing o r water-proofing materials, which consists in placing soft leather scrap together with cotton and wool fibers in a beat- In testimony whereof, I have hereunto .signed my name, at Maurer, N. J this 24th day of February 1916.

CHARLES N. FORREST. Witnesses:

M. A. BRAM, J. M. WALSH. 

